1. Field of the Invention
The present invention relates to a disk drive, and more particularly to a head assembly for use in a disk drive.
2. Description of the Related Art
In recent years, a magnetic disk drive as a kind of external storage for a computer has been desired to have a small size and a large storage capacity. A method for increasing the storage capacity of a magnetic disk drive is to increase the number of magnetic disks mounted on a spindle motor, and accordingly the spacing of the magnetic disks mounted tends to be decreased in a recent magnetic disk drive. A contact start stop (CSS) type flying magnetic head slider is widely used in a recent magnetic disk drive. The CSS type flying magnetic head slider comes into contact with a magnetic disk in stopping the operation of the magnetic disk drive, while flying a microscopic height from the surface of the magnetic disk by the action of an air flow produced over the surface of the magnetic disk rotating at a high speed in recording/reproducing information.
The CSS type flying magnetic head slider includes an electromagnetic transducer (magnetic head element) for reading/writing information from/to the magnetic disk. The magnetic head slider is supported by a suspension. When the rotation of the magnetic disk is stopped, the magnetic head slider including the electromagnetic transducer comes into contact with the disk surface, whereas when the magnetic disk is in rotation, the electromagnetic transducer included in the magnetic head slider supported to the suspension is moved above the disk surface to a desired track, thereby recording/reproducing information with the electromagnetic transducer.
A portable personal computer such as a notebook personal computer is often carried, and it is therefore required to have high shock resistance. Accordingly, such a personal computer generally employs a load/unload type magnetic disk drive designed so that a head slider is unloaded from the surface of a magnetic disk when the computer is powered off or put into a sleep mode and that the head slider is loaded to the surface of the magnetic disk when the computer is operated. That is, in the load/unload type magnetic disc drive, when the computer is powered off or put into a sleep mode, a horn portion formed at the front end of the head slider is seated on a ramp (inclined portion) of a ramp member provided near the outer circumference of the magnetic disk to retract the head slider flying a microscopic height above the disk surface from the magnetic disk. Accordingly, even when the computer receives shock, it is possible to avoid the possibility that the head slider may collide with the magnetic disk to damage it.
Both in the CSS type magnetic disk drive and in the load/unload type magnetic disk drive, data writing to the magnetic disk and data reading from the magnetic disk are performed by using a read/write head integrated circuit (head IC) mounted on a main printed circuit board provided in the magnetic disk drive. In writing data, a write signal is supplied from the head IC through a relay flexible printed circuit sheet (relay FPC) to the magnetic head element, and the data is written onto the magnetic disk by the magnetic head element according to the write signal. In reading data, a very small electrical signal read by the magnetic head element is supplied through the relay FPC to the head IC incorporating a preamplifier, and this signal is amplified in the head IC.
Thus, the data recorded on the magnetic disk is read by the magnetic head element (electromagnetic transducer). However, since the head IC is mounted on the main printed circuit board in the prior art, the distance between the magnetic head element and the head IC is large, so that a data transfer rate is low. It is considered that the data transfer rate can be increased by mounting the head IC on the suspension in adjacent relationship with the magnetic head slider. However, in the case of simply mounting the head IC on the suspension, the temperature of the head IC becomes high because it is a highly heating element. As a result, the reliability of the head IC is reduced to cause a difficulty in practical use.
It is therefore an object of the present invention to provide a disk drive which can sufficiently radiate the heat generated from a head IC mounted on a suspension.
It is another object of the present invention to provide a head assembly which can efficiently radiate the heat generated from a head IC mounted on a suspension.
In accordance with an aspect of the present invention, there is provided a disk drive comprising a housing; an actuator arm rotatably mounted in the housing; a suspension fixed at a base end portion thereof to a front end portion of the actuator arm; a head slider mounted on a front end portion of the suspension and having an electromagnetic transducer; a head IC mounted on the suspension; and a radiating flexible printed circuit sheet mounted on the suspension and the actuator arm, the radiating flexible printed circuit sheet having a first end portion fixed to the suspension and thermally connected to the head IC and a second end portion fixed to the actuator arm.
The suspension has a first printed wiring pattern for connecting the electromagnetic transducer and the head IC and a second printed wiring pattern for connecting the head IC to an external circuit. Preferably, the head IC is connected through metal bumps to the first and second printed wiring patterns. Preferably, the radiating flexible printed circuit sheet comprises an insulating layer formed of polyimide or the like and a copper foil embedded in the insulating layer. The disk drive further comprises a relay flexible printed circuit sheet bonded to a side surface of the actuator arm, and the second printed wiring pattern is connected to the relay flexible printed circuit sheet.
With the above structure of the disk drive according to the present invention, the heat generated from the head IC mounted on the suspension can be efficiently transferred through the radiating flexible printed circuit sheet to the actuator arm, thereby preventing a temperature rise of the head IC to a given temperature or higher.
In accordance with another aspect of the present invention, there is provided a head assembly comprising a suspension; a head slider mounted on a front end portion of the suspension and having an electromagnetic transducer; a head IC mounted on the suspension; and a radiating flexible printed circuit sheet mounted on the suspension, the radiating flexible printed circuit sheet having a first end portion fixed to the suspension and thermally connected to the head IC and a second end portion extending beyond a base end portion of the suspension.
Preferably, the suspension has a first printed wiring pattern for connecting the electromagnetic transducer and the head IC and a second printed wiring pattern for connecting the head IC to an external circuit.
The above and other objects, features and advantages of the present invention and the manner of realizing them will become more apparent, and the invention itself will best be understood from a study of the following description and appended claims with reference to the attached drawings showing some preferred embodiments of the invention.